In-system programmable (ISP) logic devices offer the advantage that they may be programmed in place, without removing them from the system in which they are connected. This saves time and makes them particularly suitable for systems that are dynamically reconfigurable.
U.S. Pat. No. 4,870,302 illustrates (FIGS. 8A and 8B) two systems for programming a group of ISP devices. In each system, the ISP are connected in series, so that the programming data must be transferred through each device in the series before arriving at the intended destination device. Similarly, U.S. application Ser. No. 07/695,356, commonly owned and incorporated by reference herein, describes an arrangement for programming a group of ISP devices that are connected in series. These arrangements suffer from the disadvantage that the devices can only be programmed one at a time and that the data must often be routed through several devices before it reaches its destination.